Watch what happens when 49ers defenders take their eyes off of Odell Beckham Jr.

It's common knowledge that the No. 1 rule of defending the Giants is not to let Odell Beckham Jr. get open, guess San Francisco didn't get the memo.

In the first quarter of Sundays matchup, Niners defenders took their eye off the sophomore receiver for just a second and a second is all it took.

That one second cost San Francisco a most appropriate forty-nine-yards. Looks like this "one year wonder" might be spilling over to the 2015 season.